1. Field of the Invention
This invention relates to photographic information input devices for cameras, and more particularly to such device which is used for setting, for example, an exposure mode such as programmed or manual mode, and the desired values of exposure factors such as the aperture and shutter speed.
2. Description of the Related Art
In the recent cameras, particularly single lens reflex cameras, an increasing number of ones whose various functions are automated and in which the user can select these automated various functions have been developed. For example, in the exposure control, there are the programmed mode in which the camera automatically sets both of the shutter speed and aperture value, the shutter priority mode in which the user sets the shutter speed and the camera automatically sets the aperture value on the basis of the object brightness and shutter speed, the aperture priority mode in which the user sets the aperture value and the camera automatically sets the shutter speed on the basis of the object brightness and the aperture value, and the manual mode in which the user sets both of the shutter speed and aperture value. Further even in the focus adjustment and film transportation, for the various functions, there are modes the user can select.
The fact that the number of modes the user can select in such a manner increases, though enabling the user to select a mode suited to an individual photographic situation, brings out a drawback that as the number of functions to be set increases, the operation becomes complicated.
To eliminate this drawback, the use of liquid crystal in the display and the use of buttons in the input members have been proposed.
This conventional proposal for improvement is, for example, U.S. patent application Ser. No. 681,021, now abandoned, (filed Dec. 13, 1984) assigned to the assignee of the present invention. In this proposal, the selection of selectable various kinds of photographic informations is performed by a selection operating switch such as a pushbutton. The particular photographic information selected by this selection operating switch, for example, the aperture value information, is then corrected by a correction operating switch such as another push-button. The photographic information selected here and the corrected state are displayed by a display device such as a liquid crystal display element. Thus, the user is made understand them. According to this method, the conventional structure having the equal number of mechanical correction dials to the number of kinds of photographic informations was improved so that, because a plurality of operating switches such as push buttons and a display were arranged, the space aspect on the camera body, the cost aspect and others could be improved.
However, the above-described conventional improved proposal took account of the fact that the user would unintentionally touch the operating switch to effect an erroneous operation since the various operating switches were arranged on both shoulder areas of the upper surface of the camera body and had a feature that the correction carries out only when two switches are simultaneously operated. Therefore, the problem of erroneous operation has been solved, but the user is being forced to use both hands in management.